Display device and method of fabricating the same

ABSTRACT

A display device includes a substrate in which a first area, a second area and a bending area between the first and second areas are defined, a plurality of pixels disposed above the substrate in the first area, a plurality of conductive layers extending to and intersecting the bending area, a protective film covering the conductive layers and disposed in the bending area, a first portion of the first area adjacent to the bending area, and a second portion of the second area adjacent to the bending area. The display device further includes a plurality of tag layers disposed in the first and second portions and connected to both ends of the conductive layers, wherein the bending area is interposed between the plurality of tag layers. The tag layers are exposed to an outside of the display device by exposure holes defined in the protective film.

CROSS-REFERENCE TO RELATED APPLICATION

This application claims priority to and the benefit of Korean PatentApplication No. 10-2017-0129120, filed on Oct. 10, 2017, the content ofwhich in its entirety is herein incorporated by reference.

BACKGROUND 1. Field

One or more aspects of example embodiments of the invention relate to adisplay device and a method of fabricating the same and, moreparticularly, to a display device including a mechanism for resistancemeasuring and a method of fabricating the same.

2. Description of the Related Art

Display devices (e.g., a monitor, iPad, a smart phone, and a tablet PC)providing images to users may include display panels displaying images.The display panels may include a liquid crystal display panel, anorganic light emitting display panel, an electrowetting display panel,and an electrophoretic display panel.

Recently, display devices having flexible display panels and stretchabledisplay panels have been developed with the technology development ofthe display devices. The flexible display panels may be foldable orrollable, and the stretchable display panel may be stretchable in atleast one direction. These display devices may be modified inpredetermined forms or may be modified in various forms by users. Thedisplay device including the flexible display panel may further includea protective substrate which is disposed under the flexible displaypanel to protect a lower portion of the flexible display panel.

SUMMARY

Aspects of embodiments of the invention provide a display deviceincluding a conductive layer which is used as a mechanism for resistancemeasuring and is located in a non-display area, and a method offabricating the same.

In some aspects of the invention, a display device includes a substratehaving a first area, a second area, and a bending area between the firstand second areas, a plurality of pixels located above the substrate inthe first area, a plurality of conductive layers extending to andintersecting the bending area, a protective film covering the conductivelayers and located in the bending area, in a first portion of the firstarea adjacent to the bending area, and in a second portion of the secondarea adjacent to the bending area, and a plurality of tag layersrespectively located in the first and second portions and connected toboth ends of the conductive layers, wherein the bending area isinterposed between the plurality of tag layers. The tag layers areexposed to an outside of the display device by exposure holes defined inthe protective film.

The conductive layers may include a semiconductor material.

The display device may further include a plurality of contact layerslocated on both ends of the conductive layers to electrically connectthe conductive layers to the tag layers.

The tag layers and the contact layers may include a conductive material.

The display device may further include a first sub-insulating layerlocated on the substrate, wherein the conductive layers are located onthe first sub-insulating layer, a second sub-insulating layer located onthe first sub-insulating layer to cover the conductive layers located onthe first sub-insulating layer, and an insulating layer located on thesecond sub-insulating layer. The protective film may be located on theinsulating layer in the bending area and in the first and secondportions, and the tag layers may be located on the insulating layer. Thecontact layers may be located on both ends of the conductive layersthrough holes penetrating the second sub-insulating layer and theinsulating layer and are electrically connected to both ends of theconductive layers.

The contact layers may include body portions located on both ends of theconductive layers through the holes so as to be electrically connectedto both ends of the conductive layers, and extensions located on theinsulating layer and extending from the body portions toward the taglayers so as to be electrically connected to the tag layers.

The tag layers may be spaced from the body portions and may be locatedon ends of the extensions so as to be electrically connected to theextensions.

The tag layers may be located on the contact layers so as to beelectrically connected to the contact layers.

The bending area may extend in a first direction, and the first area,the second area, and the bending area may be arranged in a seconddirection intersecting the first direction.

The conductive layers may extend in the second direction.

The display device may further include a scan driver located above thesubstrate in a third portion of the first area which does not overlapthe first portion and connected to the pixels through scan linesextending in the first direction, an emission driver located above thesubstrate in the third portion and connected to the pixels throughemission lines extending in the first direction, and a data driverlocated above the substrate in a fourth portion of the second area whichdoes not overlap the second portion and connected to the pixels throughdata lines. The data lines may extend in the second direction in thesecond portion, may extend radially in the bending area and in the firstportion, and may extend in the second direction in the third portion.The conductive layers may be located with the data lines interposedtherebetween, and the tag layers may be located with the data linesinterposed therebetween.

The substrate may have flexibility and the bending area may be bent suchthat the second area is located under the first area.

The substrate may include a base substrate having flexibility, aprotective substrate located under the base substrate and havingflexibility, and an adhesive member located between the base substrateand the protective substrate to adhere the base substrate to theprotective substrate. A bottom of the base substrate in the bending areamay be exposed through an opening defined by removing a portion of theprotective substrate overlapping with the bending area.

In some aspects of the invention, a method of fabricating a displaydevice includes preparing a display panel including a base substratehaving a first area, a second area and a bending area between the firstand second areas, a protective substrate located under the basesubstrate, an adhesive member adhering the base substrate and theprotective substrate, conductive layers located above the base substrateand intersecting the bending area, and a plurality of pixels locatedabove the base substrate in the first area, irradiating a CO₂ laser intothe protective substrate at a first boundary between the bending areaand the first area, and a second boundary between the bending area andthe second area to cut portions of the protective substrate at the firstboundary and the second boundary, irradiating an ultraviolet laser intothe bending area to reduce adhesive strength between the adhesive memberand the base substrate in the bending area, measuring a resistance ofthe conductive layers to which the ultraviolet laser is irradiated inthe bending area, stopping the irradiating of the ultraviolet laser whenthe measured resistance is equal to or less than a reference resistancevalue, and separating the protective substrate of the bending area fromthe base substrate.

BRIEF DESCRIPTION OF THE DRAWINGS

The above and other aspects and features of the present invention willbecome more apparent by reference to the following detailed descriptionwhen considered in conjunction with the accompanying drawings, in which:

FIG. 1 is a plan view illustrating a display device according to someembodiments of the invention;

FIG. 2 is an enlarged view of one of the tag portions of FIG. 1;

FIG. 3 is an equivalent circuit diagram of a pixel illustrated in FIG.1;

FIG. 4 is a cross-sectional view illustrating the pixel of FIG. 3;

FIG. 5 is a cross-sectional view taken along a line I-I′ of FIG. 2;

FIG. 6 is a side view illustrating the display device of FIG. 1 whenviewed in a first direction;

FIGS. 7 to 10 are schematic views illustrating a method of fabricating adisplay device, according to some embodiments of the invention;

FIGS. 11 to 13 are schematic views illustrating tag portions of displaydevices according to some embodiments of the invention; and

FIG. 14 is a cross-sectional view taken along a line II-II′ of FIG. 13.

DETAILED DESCRIPTION

Hereinafter, example embodiments will now be described in more detailwith reference to the accompanying drawings, in which like referencenumbers refer to like elements throughout. The present invention,however, may be embodied in various different forms, and should not beconstrued as being limited to only the illustrated embodiments herein.Rather, these embodiments are provided as examples so that thisdisclosure will be thorough and complete, and will fully convey theaspects and features of the present invention to those skilled in theart. Accordingly, processes, elements, and techniques that are notnecessary to those having ordinary skill in the art for a completeunderstanding of the aspects and features of the present invention maynot be described. Unless otherwise noted, like reference numerals denotelike elements throughout the attached drawings and the writtendescription, and thus, descriptions thereof will not be repeated. In thedrawings, the relative sizes of elements, layers, and regions may beexaggerated for clarity and ease of description.

In the following description, for the purposes of explanation, numerousspecific details are set forth to provide a thorough understanding ofvarious embodiments. It is apparent, however, that various embodimentsmay be practiced without these specific details or with one or moreequivalent arrangements. In other instances, well-known structures anddevices are shown in block diagram form in order to avoid unnecessarilyobscuring various embodiments.

It will be further understood that the terms “comprises,” “comprising,”“includes” and/or “including,” when used in this specification, specifythe presence of stated features, integers, steps, operations, elementsand/or components, but do not preclude the presence or addition of oneor more other features, integers, steps, operations, elements,components and/or groups thereof.

It will be understood that when an area or element is referred to asbeing “on,” “connected to,” or “coupled to” another area or element, itmay be directly on, connected, or coupled to the other area or element,or intervening areas or elements may be present therebetween.Conversely, when an area or element is referred to as being “directlyon,” “directly connected to,” or “directly coupled to” another area orelement, there are no intervening areas or elements therebetween. Inaddition, it will also be understood that when an area or element isreferred to as being “between” two areas or elements, it can be the onlyarea or element between the two areas or elements, or one or moreintervening areas or elements may also be present.

Unless otherwise defined, all terms used herein (including technical andscientific terms) have the same meaning as commonly understood by thoseskilled in the art to which this invention pertains. It will be furtherunderstood that terms, such as those defined in commonly useddictionaries, should be interpreted as having a meaning that isconsistent with their meaning in the context of the relevant art andwill not be interpreted in an ideal or excessively formal sense unlessclearly defined in the present specification.

Further, the use of “may” when describing embodiments of the presentinvention refers to “one or more embodiments of the present invention.”As used herein, the terms “use,” “using,” and “used” may be consideredsynonymous with the terms “utilize,” “utilizing,” and “utilized,”respectively. Also, the term “exemplary” is intended to refer to anexample or illustration.

It will be understood that, although the terms “first,” “second,”“third,” etc., may be used herein to describe various elements,components, regions, layers and/or sections, these elements, components,regions, layers and/or sections should not be limited by these terms.These terms are used to distinguish one element, component, region,layer or section from another element, component, region, layer orsection. Thus, a first element, component, region, layer or sectiondescribed below could be termed a second element, component, region,layer or section, without departing from the spirit and scope of thepresent invention.

When a certain embodiment may be implemented differently, a specificprocess order may be performed differently from the described order. Forexample, two consecutively described processes may be performedsubstantially at the same time or performed in an order opposite to thedescribed order.

Expressions such as “at least one of,” when preceding a list ofelements, modify the entire list of elements and do not only modify theindividual elements of the list. For the purposes of this disclosure,“at least one of X, Y, and Z” and “at least one selected from the groupconsisting of X, Y, and Z” may be construed as X only, Y only, Z only,or any combination of two or more of X, Y, and Z, such as, for instance,XYZ, XYY, YZ, and ZZ. As used herein, the term “and/or” includes any andall combinations of one or more of the associated listed items.

As used herein, the terms “substantially,” “about,” “approximately” andsimilar terms are used as terms of approximation and not as terms ofdegree, and are intended to account for the inherent deviations inmeasured or calculated values that would be recognized by those ofordinary skill in the art. Further, these terms as used herein areinclusive of the stated value and means within an acceptable range ofdeviation for the particular value as determined by one of ordinaryskill in the art, considering the measurement in question and the errorassociated with measurement of the particular quantity (i.e., thelimitations of the measurement system). For example, “about” may meanwithin one or more standard deviations, or within ±30%, 20%, 10%, 5% ofthe stated value.

FIG. 1 is a plan view illustrating a display device according to someembodiments of the invention. FIG. 2 is an enlarged view of one of thetag portions of FIG. 1.

Referring to FIGS. 1 and 2, a display device 100 according to someembodiments of the invention may include a display panel 110, a scandriver 120, a data driver 130, an emission driver 140, and a pluralityof tag portions TGP. The display panel 110 may be an organic lightemitting display panel. However, embodiments of the invention are notlimited thereto or thereby. In some embodiments, the display panel 110may be one of other various display panels, such as a liquid crystaldisplay panel, an electrowetting display panel, and an electrophoreticdisplay panel.

The display panel 110 may be a flexible display panel. For example, thedisplay panel 110 may include a substrate formed of a plastic materialhaving flexibility and a plurality of electronic elements disposed on orabove the substrate. The display panel 110 may have a rectangular shapewhich has short sides parallel to a first direction DR1 and long sidesparallel to a second direction DR2 intersecting the first direction DR1.

The scan driver 120, the data driver 130, and the emission driver 140may be defined as a driving part for driving the display panel 110. Thescan driver 120, the data driver 130, and the emission driver 140 mayprovide driving signals to the display panel 110 for driving the displaypanel 110, and the display panel 110 may generate an image in responseto the driving signals.

The display panel 110 may have a flat surface (or a plane or planararea) parallel to the first direction DR1 and the second direction DR2.A first area A1, a second area A2, and a bending area BA between thefirst area A1 and the second area A2 may be defined in the flat surfaceof the display panel 110. The display panel 110 may include a substrate(illustrated in FIGS. 4 and 5), and the first area A1, the second areaA2, and the bending area BA may also be defined in a planar area of thesubstrate. The bending area BA may extend in the first direction DR1.The first area A1, the bending area BA, and the second area A2 may bearranged in the second direction DR2.

Hereinafter, a portion of the first area A1, which is adjacent to thebending area BA, is defined as a first portion PT1. A portion of thesecond area A2, which is adjacent to the bending area BA, is defined asa second portion PT2. A remaining portion of the first area A1 exceptthe first portion PT1 (e.g., which does not overlap the first portionPT1) is defined as a third portion PT3. A remaining portion of thesecond area A2 except the second portion PT2 (e.g., which does notoverlap the second portion PT2) is defined as a fourth portion PT4.

The third portion PT3 may include a display area DA and a non-displayarea NDA surrounding the display area DA. The display area DA may be anarea in which an image is displayed, and the non-display area NDA may bean area in which an image is not displayed. The second area A2 and thebending area BA may be areas in which an image is not displayed. Thearea which does not display an image may be defined as a bezel area.

The display panel 110 may include a plurality of pixels PX, a pluralityof scan lines SL1 to SLm, a plurality of data lines DL1 to DLn, and aplurality of emission lines EL1 to ELm. Here, ‘m’ and ‘n’ are naturalnumbers. One pixel PX is illustrated in FIG. 1 for the purpose of easeand convenience of description and illustration. However, the pluralityof pixels PX is substantially disposed in the display panel 110. Thepixels PX may be arranged in a matrix form in the display area DA andmay be connected to the scan lines SL1 to SLm, the data lines DL1 toDLn, and the emission lines EL1 to ELm.

The scan driver 120 and the emission driver 140 may be disposed in thenon-display area NDA, and the data driver 130 may be disposed in thefourth portion PT4 of the second area A2. The scan driver 120 may bedisposed in the non-display area NDA adjacent to a first side (e.g., oneof the long sides) of the display panel 110. The emission driver 140 maybe disposed in the non-display area NDA adjacent to another side (e.g.,opposite to the first side) of the display panel 110. The data driver130 may be fabricated in an integrated circuit form and may be mountedin the fourth portion PT4.

The scan lines SL1 to SLm may extend in the first direction DR1 and maybe connected to the scan driver 120. The scan lines SL1 to SLm mayreceive scan signals from the scan driver 120. The data lines DL1 to DLnmay be connected to the data driver 130 and may receive data voltagesfrom the data driver 130. The data lines DL1 to DLn may extend in thesecond direction DR2 in the second portion PT2 and may extend radially(e.g., at an angle with respect to the first and second directions DR1,DR2) in the bending area BA and in the first portion PT1. In addition,the data lines DL1 to DLn may extend in the second direction DR2 in thethird portion PT3 so as to be connected to the pixels PX. The emissionlines EL1 to ELm may extend in the first direction DR1 and may beconnected to the emission driver 140. The emission lines EL1 to ELm mayreceive emission signals from the emission driver 140.

The scan driver 120 may generate a plurality of scan signals, and thescan signals may be applied to the pixels PX through the scan lines SL1to SLm. The scan signals may be applied sequentially to the pixels PX.The data driver 130 may generate a plurality of data voltages, and thedata voltages may be applied to the pixels PX through the data lines DL1to DLn. The emission driver 140 may generate a plurality of emissionsignals, and the emission signals may be applied to the pixels PXthrough the emission lines EL1 to ELm.

In some embodiments, the display device 100 may include a timingcontroller to control operations of the scan driver 120, the data driver130, and the emission driver 140. The timing controller may generate ascan control signal, a data control signal, and an emission controlsignal in response to control signals received from the outside (e.g.,outside of the display device 100). In addition, the timing controllermay receive image signals from the outside and may convert a data formatof the image signals to adapt the image signals to interfacespecifications of the data driver 130. The timing controller may providethe image signals, the data format of which is converted, to the datadriver 130.

The scan driver 120 may generate the scan signals in response to thescan control signal, and the emission driver 140 may generate theemission signals in response to the emission control signal. The datadriver 130 may receive the image signals, the data format of which isconverted, and may generate the data voltages corresponding to the imagesignals in response to the data control signal.

The pixels PX may receive the data voltages in response to the scansignals. The pixels PX may emit light having a brightness correspondingto the data voltages in response to the emission signals, therebydisplaying an image. Light emitting times of the pixels PX may becontrolled by the emission signals.

The tag portions TGP may be disposed in the bending area BA and thefirst and second portions PT1 and PT2. The tag portions TGP may extendin the second direction DR2 to intersect the bending area BA. In theregion of the first and second portions PT1 and PT2, the data lines DL1to DLn may be interposed between separate tag portions TGP, such thatthe tag portions TGP may not overlap with the data lines DL1 to DLn. Twotag portions TGP are illustrated as an example in FIG. 1. However, thenumber of the tag portions TGP is not limited thereto or thereby.

Referring to FIG. 2, each of the tag portions TGP may include aplurality of conductive layers CL, a plurality of contact layers CTL,and a plurality of tag layers TGL. The conductive layers CL may extendin the second direction DR2 to intersect the bending area BA and may bedisposed in the bending area BA and the first and second portions PT1and PT2. Both ends of each of the conductive layers CL may berespectively disposed in the first and second portions PT1 and PT2, withthe bending area BA interposed therebetween. Two conductive layers CLare illustrated as an example in FIG. 2. However, the number of theconductive layers CL is not limited thereto or thereby.

The conductive layers CL may be disposed with the data lines DL1 to DLninterposed therebetween (e.g., between conductive layers CL of separatetag portions TGP), and the tag layers TGL may also be disposed with thedata lines DL1 to DLn interposed therebetween, as illustrated in FIG. 1.The contact layers CTL may also be disposed with the data lines DL1 toDLn interposed therebetween.

The tag layers TGL and the contact layers CTL may include a conductivematerial. The respective tag layers TGL may be disposed adjacent to bothends of each of the conductive layers CL in the first and secondportions PT1 and PT2, and may be electrically connected to both ends ofeach of the conductive layers CL. The contact layers CTL may be disposedon both ends of each of the conductive layers CL in the first and secondportions PT1 and PT2, and may electrically connect the conductive layersCL to the respective tag layers TGL.

The contact layers CTL may include body portions BD disposed on bothends of each of the conductive layers CL so as to be electricallyconnected to the conductive layers CL, and extensions EX extending fromthe body portions BD. The tag layers TGL may be spaced apart from thebody portions BD, and the extensions EX may extend toward the tag layersTGL so as to be electrically connected to the tag layers TGL,respectively. Ends of the extensions EX may overlap with the tag layersTGL. The tag layers TGL may be exposed to the outside (e.g., outside thedisplay device 100). This will be described in more detail below.

The conductive layers CL may include a semiconductor material or a metalmaterial. When laser is irradiated into the conductive layers CL,resistances of the conductive layers CL may be changed depending on anirradiation time of the laser. A function of the conductive layers CLusing the change in resistance of the conductive layers CL will bedescribed in more detail with reference to FIGS. 7 to 10.

The bending area BA may be bent toward a bottom surface of the displaypanel 110, and the second area A2 in which the data driver 130 isdisposed may be disposed under the first area A1 of the display panel110 after bending (see FIG. 10).

FIG. 3 is an equivalent circuit diagram of a pixel illustrated in FIG.1.

One pixel PX is illustrated in FIG. 3. However, the pixels PX disposedin the display panel 110 may have the same or similar structure orconfiguration as the pixel PX illustrated in FIG. 3.

Referring to FIG. 3, the pixel PX may be connected to a correspondingscan line SLi of the scan lines SL1 to SLm, a corresponding data lineDLj of the data lines DL1 to DLn, and a corresponding emission line ELiof the emission lines EL1 to ELm. Here, “i” is a natural number equal toor less than ‘m’, and ‘j’ is a natural number equal to or less than ‘n’.

The pixel PX may include a light emitting element OLED, a drivingtransistor T1, a capacitive element Cst, a switching transistor T2, andan emission control transistor T3. The light emitting element OLED maybe an organic light emitting diode.

A source terminal of the driving transistor T1 may be provided with afirst voltage ELVDD, and a drain terminal of the driving transistor T1may be connected to a source terminal of the emission control transistorT3. A gate terminal of the driving transistor T1 may be connected to adrain terminal of the switching transistor T2.

A gate terminal of the switching transistor T2 may be connected to thescan line SLi, and a source terminal of the switching transistor T2 maybe connected to the data line DLj. A first electrode of the capacitiveelement Cst may be connected to the source terminal of the drivingtransistor T1, and a second electrode of the capacitive element Cst maybe connected to the gate terminal of the driving transistor T1.

A gate terminal of the emission control transistor T3 may be connectedto the emission line ELi, and a drain terminal of the emission controltransistor T3 may be connected to an anode electrode of the lightemitting element OLED. A cathode electrode of the light emitting elementOLED may receive a second voltage ELVSS. A level of the second voltageELVSS may be lower than a level of the first voltage ELVDD.

The switching transistor T2 may be turned-on in response to a scansignal SCAN provided through the scan line SLi. The turned-on switchingtransistor T2 may provide a data voltage DATA received through the dataline DLj to the gate terminal of the driving transistor T1. Thecapacitive element Cst may store the data voltage DATA applied to thegate terminal of the driving transistor T1 and may retain the storeddata voltage DATA after the switching transistor T2 is turned-off.

The gate terminal of the emission control transistor T3 may receive anemission signal EM through the emission line ELi, and thus the emissioncontrol transistor T3 may be turned-on. The turned-on emission controltransistor T3 may provide a current loled flowing through the drivingtransistor T1 to the light emitting element OLED. The pixel PX may emitlight while the emission signal EM is applied to the emission controltransistor T3. An intensity of the light emitted from the light emittingelement OLED may be changed depending on the amount of the currentloled.

The transistors T1 to T3 of the pixel PX may be PMOS transistors in FIG.4. However, embodiments of the invention are not limited thereto orthereby. In some embodiments, the transistors T1 to T3 of the pixel PXmay be NMOS transistors. The transistors T1 to T3 of the pixel PX may bedefined as driving elements.

FIG. 4 is a cross-sectional view illustrating the pixel of FIG. 3.

Referring to FIG. 4, the pixel PX may include a light emitting elementOLED and a transistor TR connected to the light emitting element OLED.The transistor TR may be the emission control transistor T3 of FIG. 3.The transistor TR and the light emitting element OLED may be disposed ona substrate SUB, and the substrate SUB may include a transparentflexible substrate formed of a plastic having flexibility.

The substrate SUB may include a base substrate BS, a protectivesubstrate PS disposed under the base substrate BS, and an adhesivemember AD disposed between the base substrate BS and the protectivesubstrate PS to adhere the base substrate BS to the protective substratePS. The protective substrate PS may define the bottom surface of thedisplay panel 110.

The base substrate BS and the protective substrate PS may be transparentflexible substrates. For example, the base substrate BS may be formed ofpolyimide (PI), and the protective substrate PS may be formed ofpolyethylene terephthalate (PET). The adhesive member AD may be asilicon-based adhesive.

A buffer layer BFL may be disposed on the substrate SUB, and aninsulating layer INS may be disposed on the buffer layer BFL. The bufferlayer BFL may include a first sub-insulating layer SINS1 disposed on thesubstrate SUB, and a second sub-insulating layer SINS2 disposed on thefirst sub-insulating layer SINS1. Each of the first and secondsub-insulating layers SINS1 and SINS2 may be an inorganic insulatinglayer including an inorganic material. For example, the firstsub-insulating layer SINS1 may include a silicon nitride (SiN_(x))layer, and the second sub-insulating layer SINS2 may include a siliconoxide (SiO_(x)) layer.

The insulating layer INS may include a first insulating layer INS1disposed on the second sub-insulating layer SINS2 of the buffer layerBFL, a second insulating layer INS2 disposed on the first insulatinglayer INS1, and a third insulating layer INS3 disposed on the secondinsulating layer INS2. Each of the first and second insulating layersINS1 and INS2 may be an inorganic insulating layer including aninorganic material, and the third insulating layer INS3 may be anorganic insulating layer including an organic material.

A semiconductor layer SM of the transistor TR may be disposed on thebuffer layer BFL. The semiconductor layer SM may include an inorganicsemiconductor such as amorphous silicon or poly-silicon or may includean organic semiconductor. Alternatively, the semiconductor layer SM mayinclude an oxide semiconductor. In some embodiments, the semiconductorlayer SM may include a source region, a drain region, and a channelregion between the source region and the drain region.

The first insulating layer INS1 may be disposed on or over the basesubstrate BS to cover the semiconductor layer SM. A gate electrode GE ofthe transistor TR may be disposed on the first insulating layer INS1 andmay overlap with the semiconductor layer SM. The gate electrode GE maybe disposed to overlap with the channel region of the semiconductorlayer SM. The second insulating layer INS2 may be disposed on the firstinsulating layer INS1 to cover the gate electrode GE. The secondinsulating layer INS2 may be defined as an interlayer insulating layer.

A source electrode SE and a drain electrode DE of the transistor TR maybe spaced apart from each other on the second insulating layer INS2. Thesource electrode SE may be connected to the source region of thesemiconductor layer SM through a first contact hole H1 penetrating thefirst and second insulating layers INS1 and INS2. The drain electrode DEmay be connected to the drain region of the semiconductor layer SMthrough a second contact hole H2 penetrating the first and secondinsulating layers INS1 and INS2.

The third insulating layer INS3 may be disposed on the second insulatinglayer INS2 to cover the source electrode SE and the drain electrode DEof the transistor TR. The third insulating layer INS3 may be defined asa planarization layer having a flat top or upper surface.

A first electrode E1 of the light emitting element OLED may be disposedon the third insulating layer INS3. The first electrode E1 may beconnected to the drain electrode DE of the transistor TR through a thirdcontact hole H3 penetrating the third insulating layer INS3. The firstelectrode E1 may be defined as a pixel electrode or an anode electrode.The first electrode E1 may include a transparent electrode or areflective electrode.

A pixel defining layer PDL exposing a predetermined portion of the firstelectrode E1 may be disposed on the first electrode E1 and the thirdinsulating layer INS3. A pixel opening PX_OP exposing the predeterminedportion of the first electrode E1 may be defined in the pixel defininglayer PDL. An area in which the pixel opening PX_OP is disposed may bedefined as a pixel area PA.

An organic light emitting layer OEL may be disposed on the firstelectrode E1 in the pixel opening PX_OP. The organic light emittinglayer OEL may include an organic material capable of generating lighthaving one of a red color, a green color, and a blue color. In otherwords, the organic light emitting layer OEL may generate one of redlight, green light, and blue light. However, embodiments of theinvention are not limited thereto or thereby. In some embodiments, theorganic light emitting layer OEL may generate white light by acombination of organic materials generating red light, green light, andblue light.

The organic light emitting layer OEL may include a low-molecular organicmaterial or a high-molecular organic material. In some embodiments, theorganic light emitting layer OEL may be formed of a multi-layer thatincludes a hole injection layer (HIL), a hole transporting layer (HTL),a light emitting layer, an electron transporting layer (ETL), and anelectron injection layer (EIL). The hole injection layer may be disposedon the first electrode E1. The hole transporting layer, the lightemitting layer, the electron transporting layer and the electroninjection layer may be sequentially stacked on the hole injection layer.

A second electrode E2 of the light emitting element OLED may be disposedon the pixel defining layer PDL and the organic light emitting layerOEL. The second electrode E2 may be defined as a common electrode or acathode electrode. The second electrode E2 may include a transparentelectrode or a reflective electrode. When the display panel 110 is afront emission type organic light emitting display panel, the firstelectrode E1 may be the reflective electrode and the second electrode E2may be the transparent electrode. When the display panel 110 is a backemission type organic light emitting display panel, the first electrodeE1 may be the transparent electrode and the second electrode E2 may bethe reflective electrode.

The light emitting element OLED may be formed in the pixel area PA andmay include the first electrode E1, the organic light emitting layerOEL, and the second electrode E2 in the pixel area PA. The firstelectrode E1 may be an anode corresponding to a hole injectionelectrode, and the second electrode E2 may be a cathode corresponding toan electron injection electrode. A first power source voltage may beapplied to the first electrode E1 and a second power source voltage, apolarity of which is opposite to that of a driving power voltage, may beapplied to the second electrode E2. Thus, light may be emitted from theorganic light emitting layer OEL of the light emitting element OLED bythe transistor TR.

Holes and electrons injected in the organic light emitting layer OEL maybe combined with each other to generate excitons, and the excitons maytransition from an excited state to a ground state to emit light fromthe light emitting element OLED. The light emitting element OLED mayemit one of the red light, the green light, and the blue light by a flowof a current, to display a piece of image information.

Hereinafter, a layer including the buffer layer BFL, the first to thirdinsulating layers INS1 to INS3, and the transistor TR is defined as acircuit layer DP-CL. One transistor TR is illustrated in FIG. 4.However, the transistors T1 to T3 of the pixel PX may be disposed as thedriving elements in the circuit layer DP-CL. A layer including the lightemitting element OLED and the pixel defining layer PDL is defined as alight emitting element layer DP-OLED.

A thin film encapsulation layer TFE may be disposed on the secondelectrode E2. The thin film encapsulation layer TFE may be disposedabove the pixel defining layer PDL to cover the pixels PX. The thin filmencapsulation layer TFE may have a multi-layered structure and mayinclude inorganic layers and organic layers. The inorganic layers mayprotect the light emitting element layer DP-OLED from water and oxygen,and the organic layers may protect the light emitting element layerDP-OLED from a foreign material such as dust particles.

FIG. 5 is a cross-sectional view taken along a line I-I′ of FIG. 2.

Referring to FIG. 5, the conductive layer CL may be disposed on thefirst sub-insulating layer SINS1, and the second sub-insulating layerSINS2 may be disposed on the first sub-insulating layer SINS1 to coverthe conductive layer CL. In the case in which the conductive layer CLincludes a semiconductor material, the semiconductor material mayinclude amorphous silicon. When a laser is irradiated into thesemiconductor material (such as amorphous silicon), a resistance of thesemiconductor material may decrease as an irradiation time of the laserincreases.

The contact layers CTL may be disposed on both ends of the conductivelayer CL through holes H penetrating the insulating layer INS and thesecond sub-insulating layer SINS2. The contact layers CTL may beelectrically connected to both ends of the conductive layer CL. Inaddition, the contact layers CTL may extend toward the tag layers TGL inthe second direction DR2 on the insulating layer INS (e.g., thirdinsulating layer INS3) and may be electrically connected to the taglayers TGL.

For example, the contact layers CTL may be formed of the same materialas the drain and source electrodes DE and SE of the transistor TR. Thetag layers TGL may be formed of the same material as the drain andsource electrodes DE and SE or the first electrode E1.

Body portions BD of the contact layers CTL may be disposed on both endsof the conductive layer CL through the holes H and may be electricallyconnected to both ends of the conductive layer CL. The extensions EX ofthe contact layers CTL may extend from the body portions BD toward thetag layers TGL in the second direction DR2 on the insulating layer INSand may be electrically connected to the tag layers TGL. The tag layersTGL may be exposed to the outside (e.g., outside of the display device100) through exposure holes EH defined in a protective film PF. The taglayers TGL may be disposed on ends of the extensions EX through theexposure holes EH and may be electrically connected to the ends of theextensions EX.

The protective substrate PS may be disposed under the base substrate BS,and a portion of the protective substrate PS overlapping with thebending area BA may be removed to define an opening OP in the protectivesubstrate PS. In the bending area BA, a bottom of the base substrate BSmay be exposed by the opening OP defined in the protective substrate PS.

FIG. 6 is a side view illustrating the display device of FIG. 1 whenviewed in a first direction.

Referring to FIG. 6, the protective substrate PS may be disposed underthe base substrate BS, and the opening OP may be defined in theprotective substrate PS. The circuit layer DP-CL may be disposed on thebase substrate BS. The transistors T1, T2, and T3 of the circuit layerDP-CL may be disposed in the display area DA. The buffer layer BFL andthe insulating layer INS of the circuit layer DP-CL may be disposed inthe first area A1, the second area A2, and the bending area BA. The scanlines SL1 to SLm, the emission lines EU to ELm, the data lines DL1 toDLn and at least portions of the tag portions TGP may be disposed in thecircuit layer DP-CL.

The light emitting element layer DP-OLED may be disposed on the circuitlayer DP-CL in the display area DA. The thin film encapsulation layerTFE may be disposed above the circuit layer DP-CL in the third portionPT3 and may encapsulate the light emitting element layer DP-OLED. Theprotective film PF may be disposed on the circuit layer DP-CL in thebending area BA and in the first and second portions PT1 and PT2. Thedata driver 130 may be disposed on the circuit layer DP-CL in the fourthportion PT4.

FIGS. 7 to 10 are schematic views illustrating a method of fabricating adisplay device, according to some embodiments of the invention.

Referring to FIG. 7, a display panel 110 may be prepared. The displaypanel 110 may be a display panel before the protective substrate PS ofthe bending area BA is removed. Laser may be irradiated into a bottom ofthe display panel 110 in the bending area BA. The laser may include aCO₂ laser and an ultraviolet (UV) laser. The UV laser may be irradiatedinto the bending area BA. The CO₂ laser may be irradiated into theprotective substrate PS of a first boundary BD1 between the bending areaBA and the first area A1, and to the protective substrate PS of a secondboundary BD2 between the bending area BA and the second area A2.

Referring to FIG. 8, probes PRB for measuring a resistance may come incontact with the tag layers TGL. The UV laser may pass through the basesubstrate BS and may be irradiated into the conductive layers CLdisposed in the bending area BA. When the UV laser is irradiated intothe conductive layers CL, the resistance of the conductive layers CL maybe changed. Here, the resistance of the conductive layers CL maydecrease as an irradiation time of the UV laser increases. The probesPRB may be in contact with the tag layers TGL to measure the resistance(or a resistance value) of the conductive layers CL.

Referring to FIG. 9, the protective substrate PS of the first and secondboundaries BD1 and BD2 may be cut by the CO₂ laser. For example,portions of the protective substrate PS disposed at the first and secondboundaries BD1 and BD2 may be melted by the CO₂ laser and may thus becut.

When the UV laser is irradiated into the bending area BA, adhesivestrength between the base substrate BS and the adhesive member AD may beweakened by the UV laser. For example, when the UV laser is irradiatedinto the base substrate BS formed of polyimide, hydrogen may begenerated from the base substrate BS to reduce or weaken the adhesivestrength between the base substrate BS and the adhesive member AD. Thus,the base substrate BS and the adhesive member AD may be separated fromeach other in the bending area BA.

Since the base substrate BS and the adhesive member AD are separatedfrom each other in the bending area BA and the portions of theprotective substrate PS of the first and second boundaries BD1 and BD2are cut, the protective substrate PS of the bending area BA may beeasily separated from the base substrate BS. The protective substrate PSof the bending area BA may be removed by the UV laser and the CO₂ laser,and thus the opening OP may be defined or formed.

Referring to FIG. 10, since the protective substrate PS of the bendingarea BA is removed, a thickness of the display device 100 in the bendingarea BA may be reduced. Thus, the bending area BA may be easily bent.The bending area BA may be bent toward the bottom surface of the displaypanel 110, and the second area A2 in which the data driver 130 isdisposed may be disposed under the first area A1 of the display panel110. Since the second area A2 is disposed under the first area A1, thebezel area of the display panel 110 may be reduced or minimized.

If the UV laser is excessively irradiated into the base substrate BS ofthe bending area BA for a time greater than a reference time, theadhesive member AD may be carbonized. In this case, particles of thecarbonized adhesive member AD may act as contaminant particles and maybe adsorbed on or in the display panel 110 and cause a defective displaypanel. In other words, a yield of display panels may be reduced by theparticles of the carbonized adhesive member AD.

However, according to the embodiments of the invention, the resistanceof the conductive layers CL to which the UV laser is irradiated may bemeasured, and the irradiation time of the UV laser may be checked usingthe measured resistance of the conductive layers CL. When the resistance(value) of the conductive layers CL is equal to or less than a referenceresistance value, the irradiation of the UV laser may be stopped. Thereference resistance value may be set to a resistance valuecorresponding to an irradiation time of the UV laser before the adhesivemember AD is carbonized.

Since the irradiation time of the UV laser is checked by measuring theresistance of the conductive layers CL, the irradiation of the UV lasermay be stopped before the adhesive member AD is carbonized. Thus, it ispossible to prevent the adhesive member AD from being carbonized byexcessive irradiation of the UV laser. As a result, the yield of thedisplay panel 110 may be improved when the display panel 110 isfabricated.

FIGS. 11 to 13 are schematic views illustrating tag portions of displaydevices according to some embodiments of the invention. FIG. 14 is across-sectional view taken along a line II-II′ of FIG. 13.

Hereinafter, differences between tag portions TGP1, TGP2 and TGP3 ofFIGS. 11 to 13 and the tag portion TGP of FIGS. 1, 2 and 5 will bemainly described for the purpose of ease and convenience in description.Except for the tag portions TGP1, TGP2 and TGP3, the other components ofdisplay devices 100_1 and 100_2 according to the embodiments of FIGS. 11to 13 may be substantially the same as the corresponding components ofthe display device 100 illustrated in FIG. 1. Hereinafter, the samecomponents in the embodiments of FIGS. 11 to 13 as in the embodiment ofFIG. 1 will be indicated by the same reference designators.

Referring to FIG. 11, contact layers CTL1 of a tag portion TGP1 may bedisposed on both ends of the conductive layer CL through the holes Hpenetrating the insulating layer INS and the second sub-insulating layerSINS2 and may be electrically connected to both ends of the conductivelayer CL. The contact layers CTL1 do not include the extensions EX,unlike the contact layers CTL illustrated in FIG. 5.

Tag layers TGL1 may be exposed to the outside through exposure holes EHdefined in the protective film PF. The tag layers TGL1 may be disposedon the contact layers CTL1 through the exposure holes EH and may beelectrically connected to the contact layers CTL1. When a display deviceis fabricated, probes PRB may come in contact with the tag layers TGL1to measure the resistance of the conductive layer CL. An interfaceexists between the contact layer CTL1 and the tag layer TGL1 in FIG. 11.However, embodiments of the invention are not limited thereto orthereby. In some embodiments, the contact layer CTL1 and the tag layerTGL1 may be formed of the same material and may constitute a singleunitary body.

Referring to FIG. 12, conductive layers CL2 of tag portions TGP2 mayextend in a direction forming a predetermined angle with the seconddirection DR2. The conductive layers CL2 may be electrically connectedto tag layers TGL2 through contact layers CTL2. Except for the extendingdirection of the conductive layers CL2, a cross-sectional structure ofthe tag portion TGP2 may be substantially the same as thecross-sectional structure of the tag portion TGP illustrated in FIG. 5.

Referring to FIGS. 13 and 14, conductive layers CL3 of tag portions TGP3may partially overlap with the bending area BA. The conductive layersCL3 may repeatedly intersect the first boundary BD1 and the secondboundary BD2 and may extend in zigzag forms in the first direction DR1.Ends of the conductive layers CL3 may be disposed in the first portionPT1 and in the second portion PT2, respectively. Tag layers TGL3 may berespectively disposed in the first portion PT1 and the second portionPT2 so as to be electrically connected to the ends of the conductivelayers CL3.

Contact layers CTL3 may be disposed on the ends of the conductive layersCL3 through holes H penetrating the insulating layer INS and the secondsub-insulating layer SINS2. The contact layers CTL3 may be electricallyconnected to the ends of the conductive layers CL3. The tag layers TGL3may be exposed to the outside through exposure holes EH defined in theprotective film PF. The tag layers TGL3 may be disposed on the contactlayers CTL3 through the exposure holes EH and may be electricallyconnected to the contact layers CTL3.

According to the embodiments of the invention, the conductive layer maybe disposed on the base substrate of the bending area of the displaypanel, and the laser may be irradiated into the bending area to removethe portion of the protective substrate disposed under the basesubstrate in the bending area. When the laser is irradiated into thebending area, the resistance of the conductive layer disposed in thebending area may be changed depending on the irradiation time of thelaser. Since the irradiation time of the laser is checked by measuringthe resistance of the conductive layer, it is possible to prevent theadhesive member between the protective substrate and the base substratefrom being carbonized. As a result, defects of the display panel causedby the carbonization of the adhesive member may be prevented.

Although example embodiments of the present invention have beendescribed, it is understood that the present invention is not limited tothese example embodiments, but various changes and modifications can bemade by one of ordinary skill in the art within the spirit and scope ofthe present invention as hereinafter claimed. As would be apparent toone of ordinary skill in the art as of the filing of the presentapplication, features, characteristics, and/or elements described inconnection with a particular embodiment may be used singly or incombination with features, characteristics, and/or elements described inconnection with other embodiments unless otherwise specificallyindicated.

Therefore, the disclosed subject matter is not to be limited to anysingle embodiment described herein, and the above-described embodimentsare to be considered illustrative and not restrictive. Accordingly, thescope of the present invention shall be determined only according to theattached claims, and equivalents thereof.

What is claimed is:
 1. A display device comprising: a substrate having afirst area, a second area, and a bending area between the first andsecond areas; a plurality of pixels located above the substrate in thefirst area; a plurality of lines connected to the pixels, the linescomprising scan lines, data lines, and emission lines; a plurality ofconductive layers extending to and intersecting the bending area; aprotective film covering the conductive layers and located in thebending area, in a first portion of the first area adjacent to thebending area, and in a second portion of the second area adjacent to thebending area; a plurality of tag layers respectively located in thefirst and second portions and connected to both ends of the conductivelayers; and a plurality of contact layers located between the conductivelayers and the tag layers to be electrically connected to the conductivelayers and the tag layers, wherein the bending area is interposedbetween the plurality of tag layers, wherein the tag layers are exposedto an outside of the display device by exposure holes defined in theprotective film, and the conductive layers and the tag layers areelectrically isolated from the lines.
 2. The display device of claim 1,wherein the conductive layers comprise a semiconductor material.
 3. Thedisplay device of claim 1, wherein the conductive layers comprise ametal material.
 4. The display device of claim 1, wherein the tag layersand the contact layers comprise a conductive material.
 5. The displaydevice of claim 1, further comprising: a first sub-insulating layerlocated on the substrate, wherein the conductive layers are located onthe first sub-insulating layer; a second sub-insulating layer located onthe first sub-insulating layer to cover the conductive layers located onthe first sub-insulating layer; and a third sub-insulating layer locatedon the second sub-insulating layer, wherein the protective film islocated on the third sub-insulating layer in the bending area and in thefirst and second portions, wherein the tag layers are located on thethird sub-insulating layer, and wherein the contact layers are locatedon both ends of the conductive layers through holes penetrating thesecond sub-insulating layer and the third sub-insulating layer and areelectrically connected to both ends of the conductive layers.
 6. Thedisplay device of claim 5, wherein the contact layers comprise: bodyportions located on both ends of the conductive layers through the holesso as to be electrically connected to both ends of the conductivelayers; and extensions located on the third sub-insulating layer andextending from the body portions toward the tag layers so as to beelectrically connected to the tag layers.
 7. The display device of claim6, wherein the tag layers are spaced from the body portions and arelocated on ends of the extensions so as to be electrically connected tothe extensions.
 8. The display device of claim 5, wherein the tag layersare located on the contact layers so as to be electrically connected tothe contact layers.
 9. The display device of claim 5, furthercomprising: an encapsulation layer located above the thirdsub-insulating layer to cover the pixels in a third portion of the firstarea which does not overlap the first portion, wherein the pixelscomprise: a plurality of driving elements located on the secondsub-insulating layer, wherein each of the driving elements comprises agate electrode, a source electrode, and a drain electrode; and aplurality of light emitting elements located on the third sub-insulatinglayer and connected to the driving elements through contact holesdefined in the third sub-insulating layer, wherein each of the lightemitting elements comprises: a first electrode connected to acorresponding one of the drain electrodes; a second electrode facing thefirst electrode; and an organic light emitting layer located between thefirst electrode and the second electrode, wherein the contact layers areformed of the same material as the drain and source electrodes, andwherein the tag layers are formed of the same material as the drain andsource electrodes or the first electrode.
 10. The display device ofclaim 1, wherein the bending area extends in a first direction, andwherein the first area, the second area, and the bending area arearranged in a second direction intersecting the first direction.
 11. Thedisplay device of claim 10, wherein the conductive layers extend in thesecond direction.
 12. The display device of claim 10, wherein theconductive layers extend in a direction forming an angle with the seconddirection.
 13. The display device of claim 10, further comprising: ascan driver located above the substrate in a third portion of the firstarea which does not overlap the first portion, and connected to thepixels through scan lines extending in the first direction; an emissiondriver located above the substrate in the third portion and connected tothe pixels through emission lines extending in the first direction; anda data driver located above the substrate in a fourth portion of thesecond area which does not overlap the second portion, and connected tothe pixels through data lines, wherein the data lines extend in thesecond direction in the second portion, extend radially in the bendingarea and in the first portion, and extend in the second direction in thethird portion, wherein the conductive layers are located with the datalines interposed therebetween, and wherein the tag layers are locatedwith the data lines interposed therebetween.
 14. The display device ofclaim 13, wherein the substrate comprises: a base substrate havingflexibility; a protective substrate located under the base substrate andhaving flexibility; and an adhesive member located between the basesubstrate and the protective substrate to adhere the base substrate tothe protective substrate, wherein a bottom of the base substrate in thebending area is exposed through an opening defined by removing a portionof the protective substrate overlapping with the bending area.
 15. Thedisplay device of claim 1, wherein the substrate has flexibility and thebending area is bent such that the second area is located under thefirst area.